ASTM B501-10(2019)
(Specification)Standard Specification for Silver-Coated, Copper-Clad Steel Wire for Electronic Application
Standard Specification for Silver-Coated, Copper-Clad Steel Wire for Electronic Application
ABSTRACT
This specification deals with silver-coated, round, copper-clad steel wires for electronic applications. The four classes of steel wires covered here are Classes 30HS, 30A, 40HS, and 40A. Specimens shall undergo tests that shall evaluate their conformance to the following physical properties: tensile strength, elongation, electrical resistivity, continuity and mass of the coating, and dimensions and density of the wire.
SCOPE
1.1 This specification covers silver-coated, round, copper-clad steel wire for electronic application.
1.2 Silver coatings in mass percentages of the total mass of the coated wire are as follows: 1.25, 2.5, 4.0, 6.1, and 8.0.
1.2.1 Silver-coated wire having different minimum percentage of silver by mass may be obtained by mutual agreement between the manufacturer and the purchaser. For information purposes, the thickness of coating in microinches provided by the mass percentages listed in 1.2 is shown in Table 1.
1.3 Four classes of copper-clad steel wire are covered as follows: Class 30HS nominal 30 % conductivity hard-drawn, Class 30A nominal 30 % conductivity annealed, Class 40HS nominal 40 % conductivity hard-drawn, and Class 40A nominal 40 % conductivity annealed.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4.1 Exception—In resistivity the SI units are to be regarded as the standard.
1.5 The following safety hazards caveat pertains to the test method described in this specification. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (Warning—Consideration should be given to toxicity and flammability when selecting solvent cleaners.)
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B501 −10 (Reapproved 2019)
Standard Specification for
Silver-Coated, Copper-Clad Steel Wire for Electronic
Application
This standard is issued under the fixed designation B501; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This specification covers silver-coated, round, copper-
clad steel wire for electronic application.
2. Referenced Documents
1.2 Silver coatings in mass percentages of the total mass of
2.1 The following documents of the issue in effect on date
the coated wire are as follows: 1.25, 2.5, 4.0, 6.1, and 8.0.
of material purchase form a part of this specification to the
1.2.1 Silver-coated wire having different minimum percent-
extent referenced herein:
age of silver by mass may be obtained by mutual agreement
2.2 ASTM Standards:
between the manufacturer and the purchaser. For information
B193 Test Method for Resistivity of Electrical Conductor
purposes, the thickness of coating in microinches provided by
Materials
the mass percentages listed in 1.2 is shown in Table 1.
B258 Specification for Standard Nominal Diameters and
1.3 Four classes of copper-clad steel wire are covered as
Cross-Sectional Areas of AWG Sizes of Solid Round
follows: Class 30HS nominal 30 % conductivity hard-drawn,
Wires Used as Electrical Conductors
Class 30A nominal 30 % conductivity annealed, Class 40HS
B452 Specification for Copper-Clad Steel Wire for Elec-
nominal 40 % conductivity hard-drawn, and Class 40A nomi-
tronic Application
nal 40 % conductivity annealed.
3. Terminology
1.4 The values stated in inch-pound units are to be regarded
3.1 Definitions of Terms Specific to This Standard:
as standard. The values given in parentheses are mathematical
3.1.1 lot—any amount of wire of one class and size pre-
conversions to SI units that are provided for information only
sented for acceptance at one time, such amount, however, not
and are not considered standard.
to exceed 10 000 lb (4500 kg) (Note 1).
1.4.1 Exception—In resistivity the SI units are to be re-
garded as the standard.
3.1.2 sample—a quantity of production units (coils, reels,
and so forth) selected at random from the lot for the purpose of
1.5 The following safety hazards caveat pertains to the test
determining conformance of the lot to the requirements of this
method described in this specification. This standard does not
specification.
purport to address all of the safety problems, if any, associated
with its use. It is the responsibility of the user of this standard
3.1.3 specimen—a length of wire removed for test purposes
to establish appropriate safety, health, and environmental
from any individual production unit of the sample.
practices and determine the applicability of regulatory limita-
NOTE 1—Alot should comprise material taken from a product regularly
tions prior to use. (Warning—Consideration should be given
meeting the requirements of this specification. Inspection of individual
to toxicity and flammability when selecting solvent cleaners.)
lots of less than 500 lb (250 kg) of wire cannot be justified economically.
1.6 This international standard was developed in accor- For small lots of 500 lb (250 kg) or less, the purchaser may agree to the
manufacturer’sregularinspectionoftheproductasawholeasevidenceof
dance with internationally recognized principles on standard-
acceptability of such small lots.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4. Ordering Information
4.1 Orders for material under this specification shall include
the following information:
This specification is under the jurisdiction of ASTM Committee B01 on
Electrical Conductors and is the direct responsibility of Subcommittee B01.06 on
Bi-Metallic Conductors. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2019. Published October 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1969. Last previous edition approved in 2015 as B501 – 10 (2015). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/B0501-10R19. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B501 − 10 (2019)
TABLE 1 Silver Mass Percent and Thickness of Coating
Thickness of Silver, µin.
Diameter Cross-Sectional Area at 20°C
(for information only)
1.25 2.5 4.0 6.1 8.0
2 2
in. mm cmil in. mm
% % % % %
0.0720 1.829 5 180 0.00407 2.63 176 352 569 876 1 158
0.0641 1.628 4 110 0.00323 2.08 156 313 507 779 1 031
0.0571 1.450 3 260 0.00256 1.65 139 279 451 694 918
0.0508 1.290 2 580 0.00203 1.31 124 248 401 618 817
0.0453 1.151 2 050 0.00161 1.04 111 222 358 551 728
0.0403 1.024 1 620 0.00128 0.823 98 197 318 490 648
0.0359 0.912 1 290 0.00101 0.653 88 176 284 437 577
0.0320 0.813 1 020 0.000804 0.519 78 156 253 389 515
0.0285 0.724 812 0.000638 0.412 70 139 225 347 458
0.0253 0.643 640 0.000503 0.324 62 124 200 308 407
0.0226 0.574 511 0.000401 0.259 55 111 179 275 363
0.0201 0.511 404 0.000317 0.205 49 98 159 244 323
0.0179 0.455 320 0.000252 0.162 44 88 141 218 288
0.0159 0.404 253 0.000199 0.128 39 78 126 193 256
0.0142 0.361 202 0.000158 0.102 35 69 112 173 228
0.0126 0.320 159 0.000125 0.0804 31 62 100 153 203
0.0113 0.287 128 0.000100 0.0647 28 55 89 137 182
0.0100 0.254 100 0.0000785 0.0507 24 49 79 122 161
0.0089 0.226 79.2 0.0000622 0.0401 22 44 70 108 143
0.0080 0.203 64.0 0.0000503 0.0324 39 63 97 129
0.0071 0.180 50.4 0.0000396 0.0255 35 56 86 114
0.0063 0.160 39.7 0.0000312 0.0201 31 50 77 101
0.0056 0.142 31.4 0.0000246 0.0159 26 44 68 90
0.0050 0.127 25.0 0.0000196 0.0127 24 40 61 80
0.0045 0.114 20.2 0.0000159 0.0103 22 36 55 72
0.0040 0.102 16.0 0.0000126 0.00811 32 49 64
0.0035 0.089 12.2 0.00000962 0.00621 28 43 56
0.0031 0.079 9.61 0.00000755 0.00487 24 38 50
4.1.1 Quantity of each size, 6. General Requirements
4.1.2 Wire size (see 7.1 and Table 1),
6.1 Tensile strength and elongation of the silver-coated wire
4.1.3 Class of basis wire (see 1.3),
shallconformtotherequirementsofSpecificationB452forthe
4.1.4 Mass percentage of coating (see 1.2 and Table 1),
applicable size and class of copper-clad steel wire.
4.1.5 Package size (see Section 12),
6.2 Resistivity—The electrical resistivity at a temperature of
4.1.6 Special packaging marking, if required, and
20°C shall not exceed the values prescribed in Table 2. See
4.1.7 Place of inspection (see 9.1).
Note 3 for calculating electrical resistance.
6.3 Continuity of Coating—Thecoatingshallbecontinuous.
5. Materials and Manufacture
The continuity of the coating shall be determined on represen-
5.1 Thebasismaterialshallconsistofcopper-cladsteelwire
tative samples taken before stranding or insulating and shall be
conforming to the product description, quality and specifica-
determined by the sodium polysulfide test, in accordance with
tion requirements of Specification B452.
10.2.3.1. Wire whose coating mass corresponds to a thickness
less than 0.00005 in. (50 µin.) shall not be subject to this test.
5.2 The silver-coated wire shall consist of the basis wire
coatedwithsilver.Thequalityofthesilver-coatedwireshallbe
6.4 Mass of Coating—The mass of coating expressed in
such that the finished product meets the properties and require-
percent of the total mass of the wire shall be not less than the
ments in this specification (Note 2).
percentage specified and referred to in this specification or the
percentage as agreed on between the manufacturer and pur-
NOTE 2—Silver coatings on copper-clad steel provide for:
chaser at the time of the placing of the order. For ease of
(a)Abarrier between the copper and insulation whose curing temperature
in the process of fabricating is too high for the use of tin-coated wires.
(b) A low contact resistance between the strands of outer conductors of
coaxial conductors used in high-frequency circuits. TABLE 2 Resistivity
(c)Alow radio-frequency resistance of conductors used in high-frequency
Resistivity, max at 20°C
circuits (skin effect). 2
Class of Wire Ω·mm /m
(d) Good solderability for high-temperature hook-up wires which prohibit
30HS and 30A 0.05862
the use of tin-coated wires due to high curing temperatures used in 40HS and 40A 0.04397
fabricating the finished wire.
B501 − 10 (2019)
comparison, the thickness of coating for various percentages 9. Sampling
has been included in Table 1.
9.1 The number of production units in a sample (Note 5)
6.5 Joints—Necessary joints in the wire and rods prior to shall be as follows:
final coating and drawing shall be made in accordance with
9.2 For elongation, resistivity, and mass of coating
good commercial practice. Joints made after coating shall not
determinations, the sample shall consist of four production
be allowed to remain in the final product.
TABLE 3 Sampling for Dimensional Measurements
First Sample Second Sample
No. of Allowable No. No. of Allowable No.
No. of Units in Lot
Units in of Defects in Units in n + n of Defects in
1 2
Sample n Sample c Sample n both Samples, c
1 1 2 2
1 to 14, incl all 0 . . 0
15 to 50, incl 14 0 . . 0
51 to 100, incl 19 0 23 42 1
101 to 200, incl 24 0 46 70 2
201 to 400, incl 29 0 76 105 3
401 to 800, incl 33 0 112 145 4
Over 800 34 0 116 150 4
NOTE 3—Relationships which may be useful in connection with the
units. For continuity of coating determinations, the sample
values of electrical resistivity prescribed in this specification are shown in
shall consist of eight production units. From each unit, one test
Table 2. Resistivity units are based on the InternationalAnnealed Copper
specimen of sufficient length shall be removed for the perfor-
Standard (IACS) adopted by IEC in 1913, which is ⁄58Ω·mm /m at 20°C
mance of the required test.
for 100 % conductivity. The values of 0.017241Ω·mm /m and the value
of 0.15328Ω·g/m at 20°C are respectively the international equivalent of
9.3 For dimensional measurements and surface finish, the
volume and mass resistivity of annealed copper equal to 100 % conduc-
samplesshallconsistofaquantityofproductionunitsshownin
tivity. The latter term means that a copper wire1min length and mass of
Table 3 under the heading “First Sample.”
1 g would have a resistance of 0.15328 Ω. This is equivalent to a
resistivity value of 875.20Ω·lb/mile , which signifies the resistance of a
9.4 For packaging inspection (when specified by the pur-
copper wire 1 mile in length with mass of 1 lb. It is also equivalent, for
2 chaseratthetimeofplacingtheorder),thesampleshallconsist
example,to1.7241µΩ/cmoflengthofacopperbar1cm incrosssection.
of a quantity of production units shown in Table 4.
A complete discussion of this subject is contained in NBS Handbook 100
of the National Institute of Standards and Technology. The use of five
significant figures in expressing resistivity does not imply the need for
TABLE 4 Sampling for Surface Finish and Packaging Inspection
greater accuracy of measurement than that specified inTest Method B193.
No. of Allowable No.
The use of five significant figures is required for complete reversible
No. Units in Lot Units in of Defective
conversion from one set of resistivity units to another.
Sample, n Units, c
1 to 30, incl all 0
7. Dimensions and Permissible Variations
31 to 50, incl 30 0
7.1 The wire sizes shall be expressed as the diameter of the 51 to 100, incl 37 0
101 to 200, incl 40 0
wire in decimal fractions of an inch to the nearest 0.0001 in.
201 to 300, incl 70 1
(0.003 mm) (Note 4). For diameters under 0.0100 in. (0.254
301 to 500, incl 100 2
mm), the wire shall not vary from the specified diameter by 501 to 800, incl 130 3
Over 800 155 4
morethan 60.0001in.(0.003mm)andfordiametersof0.0100
in. (0.254 mm) and over, the wire shall not vary from the
specified diameter by more than 61 %, expressed to the
NOTE 5—Cumulative results secured on the product of a single
nearest 0.0001 in. (0.003 mm).
manufacturer indicating continued conformance to the criteria, are neces-
NOTE 4—The values of the wire diameters in Table 1 are given to the sary to ensure an overall product meeting the requirements of this
specification. The sample size and conformance criteria given for the
nearest 0.0001 in. and correspond to the standard sizes given in Specifi-
cation B258. The use of gage numbers to specify wires is not recognized various characteristics are applicable only to lots produced under these
conditions.
in this specification because of the possibility of confusion. An excellent
discussion of wire gages and related subjects is contained in NBS
10. Test Methods
Handbook 100 of the National Institute of Standards and Technology.
10.1 For tensile strength, elongation, resistivity, dimen-
8. Workmanship, Finish, and Appearance
sional measurement and the quality of the basis wire, the latest
8.1 The coating shall consist of a smooth, continuous layer,
issue of Specification B452 shall apply and the tests shall be
firmly adherent to the surface of the copper. The wire shall be
performed on the silver-coated wire (Note 6).
bright and free from all imperfections not consistent with good
NOTE 6—It is known that the rate of loading during tension testing
commercial practice.
affects the performance of the sample to a greater or lesser extent
depending upon many factors. In general, tested values of tensile strength
Available from National Institute of Standards and Technology (NIST), 100 are increased and tested values of elongation are reduced with increase of
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. speed of the moving head of the testing machine. In the case of tests on
B501 − 10 (2019)
soft or annealed wire, however, the effects of speed of testing are not
10.2.3 Procedure:
pronounced. Tests of soft wire made at speeds of moving head which
10.2.3.1 Immersion in Polysulfide Solution—Immerse a
under no-load conditions are not greater than 12 in./min (300 mm/min) do
length of at least 4 ⁄2 in. (115 mm) from each of the clean
not alter the final results of tens
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